As a discharge device, a foam discharge device including a pump having a stem downwardly movably erected at a mouth section of a container main body in which a liquid is accommodated in an upwardly biased state and a pressing head disposed at an upper end section of the stem to form a nozzle hole, and a mounting cap configured to mount a pump on the mouth section of the container main body is known in the related art. In such a foam discharge device, a pump configured to form and discharge a liquid in a container main body from a nozzle hole includes a piston for a liquid linked to the stem, a cylinder for a liquid in which the piston for a liquid is vertically slidably accommodated, a piston for air linked to the stem, a cylinder for air in which the piston for air is vertically slidably accommodated, and an air-liquid mixing unit configured to mix the liquid from the cylinder for a liquid and the air from the cylinder for air to foam the liquid (for example, see Patent Document 1).